Here's the url for the fbi's tips and public leads web form:
https://tips.fbi.gov/ Not good at html so maybe someone else could post with an active link.
It was a little intimidating filling out the tip, as they want all your personal information, but damn-it, I'm a U.S citizen and I'm just asking them to do their job and follow up on crimes reported by a major newspaper that are going un investigated, so what the hell, if they want to start a file on me, let them!